questions and answers about japanese hot tubs, mainenance and hinoki wood qualities

enjoying life, japanese style - by Bartok design

FAQs:

SIMPLICITY + SATISFACTION:
Installing a wood bath tub might be thrilling for you and
a little worrisome for your contractorif he is doing it for the first time.
Actually, installation, use and maintenance of a hinoki bathtub is very
straightforward and you will be surprised how simple it is. Please look
at the FAQ`s below and feel free to ask anything you do not understand.

It depends on the size of the tub and ... how intimate are the 2 people using the tub.
The round outlet tub is 3ft in diameter (external size) so I think it works best for one person.

You may make a test in a tub you own or create a mockup in your living room using a corner of the room and the back of a sofa, or some cardboard boxes to simulate the size.
We can build the size to match your specs so it can fit your needs/space in the most efficient way.

We are looking forward to working with you and remain at you disposal for any question/problem.

Shipping insurance: as you say, it is included, in case there is any problem just be sure to report it asap. Just for your reference, until now we did not have one single damage report.

Guarantee: please note that we cannot provide a guarantee on hinoki tubs.
The wood is very sensitive to environmental conditions and we cannot be responsible for any damage caused by dryness, mold or detergents.
We will do our best to assist with any problem, but are simply not able to implement the conditions for a guarantee on the product.

Of course if there is a construction problem or execution miss we will repair or replace the tub.
Please note that in over 12 years (201 tubs delivered worldwide) we replaced one tub (non compatible water-repellent) and repaired one (dead knot).

The quick answer is: for Germany the import tax on wooden items is 0%. The VAT is 19%.
For people who want to know more: please find here the master chart:
everything you always wanted to know about import taxes ... and never dared to ask!Please note that we export wooden tubs with the following customs HS code: 4421.90

1) As you know, japanese onsen are usually not equipped with jets.
Often there are some shallow "bed type" jacuzzi tubs for individual use.
Some people may feel that japanese bathing has a precise ritual and aesthetics and does need the bubbles. Others may appreciate the jets as an upgraded and more luxurious japanese tub.
This choice depends on your clientele and on the services that you offer in your establishment.
If you decide to use jets, there is no incompatibility with wooden tubs. Anyway we would recommend you to ship us the nozzles so we can seamlessly embed them in the locations as per your instructions.
Many small air outlets on the bottom of the tub (air-blower) are not recommended as they weaken the structure of the tub.

Thank you for your interest in our hinoki products.
The tubs are made in japan using the traditional Edo carpentry technique.
They can be converted to jacuzzis but we cannot supply this equipment from here.
It is better and cheaper to do it on site (all the best spa equipment is american, such as Pentair, Waterways, Hayward, Jandy etc.)
In this way there is no problem for maintenance/replacement parts. Please try to contact a local pool/spa equipment supplier and ask for their advice.

Basically our tubs are made in solid wood and is very easy to open holes anywhere is needed to apply the jets.

We are looking forward to working with you and remain at your disposal for any question.

Thank you for your interest in our japanese bathtubs!
We need about 3 weeks for production and 1wk for shipping with ocean
freight so the timeframe is very tight.
Please let me know the sizes you are looking at and we will provide a
quotation and drawing for your reference.
About the bubbles, we cannot supply equipment because of the difficulty
to provide assistance, spare parts etc.
We recommend to use spa equipment available in the US (Waterways,
Hayward, Jandy, Pentair, Certkin etc!)
Check with a spa equipment company what they recommend for a tub with 1
1/2" thick bottom. Of course the wood thickness can be partially reduced
on the back if needed (with a trimmer, around the blower noozle socket)

We are looking forward to working with you and remain at you disposal
for any question/problem.

Thank you for your interest in our japanese bathtubs.
There are some precautions to be taken when installing a wooden bathub.The main point is to maintain a balanced relative humidity between 40 and 60%, which is by the way also an optimal environment for pianos, antique furniture, and of course human beings!

For this reason you should avoid elements that can dehydrate the wood:- floor heating under the tub
- heating elements in the bathroom in general
- central air conditioning (most types include a humidity control battery)- expose the tub to direct sun radiation
- leaving the tub unused for an extended period of time

Good practice is:- use the tub at least 3 times a week. This routine restores the optimal wood humidity.
(Also, while the tub is full of water, you can use heating and AC or expose the tub to direct sun radiation

Acceptable practice is:- leave some water inside the tub and cover it.
This should be done in case the tub is left unused for one week or more.
Anyway you should still not use heating or AC as the humidity of the wood of the external side of the tub will differ from the humidity inside and may cause the wood to warp.
Since leaving water inside the tub may cause stains and originate a water-line, we recommend to leave a bassinet with water inside and place it inside the tub. If the tub is covered, the humidity will be trapped inside and will be enough to keep the wood hydrated.

I hope this answered your question.

We are looking forward to working with you and remain at you disposal for any question/problem.

Please note:
1) We cannot install pop-up drain fittings.
Basically, there are no standard fittings for a thick bottom plank such as a wooden bath.
Even if we were to modify a socket and adapt it, we could not be responsible for mechanical problems, spare parts etc. so we prefer to stick to a rubber plug type.
If you prefer, we also have a spherical shape available.http://www.bartokdesign.com/japan/0-blog_news/spherical_drain_plug_1.php

2) Yes, we can place the drain on one side, please note that we recommend an offset of 55mm from the internal wall face.
On the other hand, if you are planning to attach the drain to the plumbing using an elbow, the "feet" under the tub will interfere with it. If you let us know the direction in which the elbow will be pointing, we will calculate the offset and place the drain accordingly.

The advance payment is 50% of the custom items (tub and platform). The balance will be the left 50% + cost of packaging, transport fee.
The payments can be done with a international bank transfer to our bank in Japan or by credit card thru Paypal.
In case of the bank transfer there will be a 6500 JPY bank fee per transaction. In case of Paypal a 4% fee on the total of each payment.
the balance payment is done before the shipping. Once the tub is completed, we will send the pictures for your verification and approval.
If you are satisfied and we can proceed with the packaging, at that point we will need the balance payment before shipping.
We just have a limited margin on this product and we cannot afford to take any risk on the payment of the tub.

Since 2009 the US customs require the importer (the customer) to fill in an "Importer security file". This is applicable only to ocean freight (so shipments by air do not require it.)

The importer security for is quite bureaucratic and time consuming.
You have to submit before the shipment leaves the port of origin otherwise there is the risk (theoretical) that your shipment may be destroyed and you may be billed for the disposal of it...
But there is no pitfall, and the staff from our forwarder will help you.
Please find more information here:

Usually, the full immersion "up to the shoulders" bath is done sitting on the bottom of the tub (so to say, without seat)
Actually traditional japanese bathtubs do not have a seat.
The seat is used for a "half body bath", for reading while in the tub or to get a pause from the full depth bath (when you feel too hot)
To have the full bath, you can sit in the tub on the opposite side of the seat . Alternatively, you can remove the seat plank.

Also consider that when you relax in the tub, rather than keeping a 90 degrees sitting posture, it is easier to slide a little forward until the feet touch the other side. (This is also why the tub should be not too long) In this case the shoulder line lowers a few inches.

We can make extra deep tubs (some examples in the custom tubs section), but the disadvantage are:
- increased specs to contain the extra water pressure (and therefore increased cost)
- you will need some steps to climb to enter and egress easily (or recess the tub in the floor)
- you will need more hot water each time.

Heating in the bathroom can damage your tub.
This can be solved by keeping water in the tub at all times (during the heating season).
Cover the tub to avoid condensation and mold in the bathroom.
The tub may get some stain also, but the hydro-repellent treatment we apply makes it easy to clean.
We cannot make a clear statement for your situation (recommend or not recommend): you have to consider the options and the risk involved.

1) The ofuro and the material for the sunoko are HS code 4421 . 90.
Other accessories or metal parts may have a different code.

2) We exported 5 times to Canada. There is no need for fumigation for finished wood products. I will verify for the lumber for the sunoko grating. Anyway we can supply a certification stating that the material is Kiln Dried and this is sufficient.
On the other hand, some some counties building dept. require compliance with the ASME regulations. Our tubs are not ASME certificated, so you should either file it as a "soaking tub" (not sanitary equipment) or contact us for more options.

3) Later today I will prepare a proforma invoice for your review and approval.
Please note that the shipping fee is still approximate. Kindly let me know your exact shipping address so I can obtain a official quote from the forwarder.

Finally, as you probably know ocean shippings for Canada require that the receiver is a corporation (private entities cannot file the customs paperwork.)

Thank you for your interest in our japanese bathtubs.
With reference to your kind question, also in japan there are many places with hard water.
Considering that in the onsen (japanese hot-springs) with thermal water containing all sorts of minerals wooden baths are used,
we can say that there is not too much to be worried about.

The scaling occurs if the water is left in the tub for long periods (es. using recirculation systems) so we would recommend to fill the tub only when in use (which works for most residential applications).
I am not a chemist, so forgive my lack of technical terms, but actually calcium tends to build up on metals or enamel, it does not stick to wood.

We are looking forward to working with you and remain at your disposal for any other question of problem.

About your existing tub, thank you for the pictures.
The wood of the tub is very dry. Also, because the wood is plank cut and not
quarter-sawn, the deformation is very severe...
On the other hand, if you re-hydrate, chances are it will be usable again.

1) Fill the gaps with clear silicon in such a way that the tub does not
leak anymore. Let dry for 1 day.
2) Fill the tub with water and let it full for 2 days.
3) empty the tub. Probably the wood will have expanded and the silicon
will have squeezed out from the cracks. Cut it flush with a cutter.

The tub should be OK and not be too bad aesthetically also.
If this does not work or does not satisfy you, we will be glad to assist
you for a new tub.

If you decide to replace it, of course we can match the center drain. Actually we can also match the tub sizes if necessary.
Basically all our tubs are made to order so there is no difference in price between standard sizes and custom sizes.
We have a standard size pricelist for pure reference.

Well a climate similar to japan you will need to:
1) in summer: provide a good natural ventilation. Once you empty the tub, wipe it with a dry cloth and leave the windows open.
A wet climate may cause mold stains. On the other hand, this problem is minimized because we use a water repellent. See the documentation on our HP:
http://www.bartokdesign.com/japan/downloads/kihadaichiban-description.pdf

2) in winter: avoid using heating equipment in the bathroom when the tub is empty. Use the tub often (at least 2 times a week) and if you leave for an extended period, leave a bucket of water inside the tub and cover it to increase the air relative humidity. Keep an hygrometer near the tub and assure that humidity does not drop below 50%.
If the climate is too dry, there is the risk of the wood drying and eventually cracking.

1) usually we slope battered ends 15 degrees (from the vertical). This is usually a detail requested by clients/local designer as they think that it would be more comfortable to sit inside. Actually, because the water makes the body float, the back assumes a comfortable angled position regardless of the tub end. From a functional point of view, straight is same as sloped. I recommend to choose the sloped option if you like the look/shape or to save a couple of gallons of hot water. The bathtub cost is same for the two options: the straight back requires less work but more material, the sloped detail involves more work but less material.

2) Yes, shapes can be customized, anyway irregular or complex shapes are not recommendable because the water pressure would cause structural problems and leakages to unbalanced shapes. We can do square, rectangular, round, ellipse with straight sides, exagonal/octagonal (depends on the size, please consult)

3) please refer to our FAQ`s. There is really no magic solution as wood is best preserved in a well balanced environment. Use the tub often (everyday is best) to maintain an optimal humidity level and avoid cracks/leaking.
For the same reasons, be sure not to use heating systems or central air conditioning in the bathroom, when the tub is not in use (empty)
To avoid insurgence of mold, open the windows after the tub has been emptied and if the weather is very humid, wipe the tub with a bathtowel after use.

Yes, wooden tubs can be used outside but some precautions must be taken to protect it from direct sunlight and dryness.
There is no problem as long as the tub is protected with a cover from direct sunlight while it is empty. A soft spa thermal cover would improve also the situation in winter and prevent the risk of cracks caused by sudden drops in temperature.
For the termites, there should be no problem, you should build it into the deck in such a way that air can circulate around.
Asnaro has a nice and relaxing aroma as well, actually more intense than hinoki.

About the mold: you should provide a good natural ventilation (open doors or windows after the tub). Forced ventilation alone, will not be enough.
In any case, we treat the tubs with a hydro-repellent product (see here).http://www.bartokdesign.com/japan/downloads/kihadaichiban-description.pdf
"KIHADA ICHIBAN" is applied by brush or roller. It does not create a coat, it actually penetrates inside offering lasting protection whithout occluding the pores of wood.

Hinoki wood is generally unfinished to convey its soft touch and natural aroma. Anyway, this new product (based on the nano-technology and using a fluoride base) operates like the silicates treatments used in europe to waterproof bricks or plaster.
These products penetrate inside the material so they do not leave a peel, they do not alter the color, luminosity and aroma of the wood.

We have been using this product for 4 years now.
It is great to prevent mold and we did not have any claim from Singapore customers so far.

1) simply planed: in this case you have to wash away immediately any spill or it will stain. If you get a stain, blot wisely with some bleach and rinse promptly until the stain is removed.

2) treated with "kihada ichiban". This product is a hydrorepellent which does not create a film on the wood. It is very safe and environmental friendly but it is a chemical product.
Please find more info here:http://www.bartokdesign.com/japan/downloads/kihadaichiban-description.pdf
In this case the spill will not penetrate the wood. The manufacturer warns that the hydrorepellent effect might diminuish after 2-3 years but in our experience we could not find considerable performance loss.

I am not a specialist but the composition of the resin within the wood fibers of Port Orford Cedar and Hinoki is very different.
Actually one of the active aromatic components which has been isolated and is frequently used for viral protection and anti-allergic products is the hinokitiol.
hinokitiol is present in Taiwanese hinoki and in Japanese Asnaro wood.
It is included only in small percentages in japanese hinoki! and if I am not wrong, it is completely absent in american cedars.
Please find more info here:http://www.bartokdesign.com/japan/0-blog_news/new_product_hiba-oil.php
If you are interested in the aromatic properties of this wood you might also consider ordering a bottle of oil and try if it works in your case.

* hinoki: white/pinkish, with a delicate lemon scented aroma. more expensive. more delicate (because it is lighter). Japanese are crazy for hinoki because of its "pure" image.

* asnaro: nice honey color. It has a stronger forest aroma. 20% cheaper than hinoki. Easier to maintain (because is slightly tanned and because contains more hinokitiol oil). Popular for export for its color and cost-performance.

Our outlet tubs are brand new, spotless tubs that were wrapped in poliethilene sheet from the very day they were completed.

An outlet tub is about 20% cheaper of a custom order tub with the same size/material.
This does not mean in any way that those tubs are faulty or old.

Most of our outlet tubs originate from 2 cases:

1) The tub was custom ordered and the client either canceled the order or asked for a size/shape modification that required a new start.

2) The tub is made optimizing some material we have in stock, in most cases left over from a larger job. We can define the sizes of the tub based on the length of the material we have - minimizing the loss - as opposed as cutting longer planks as we have to do for a custom order tub.
Secondly, we produce sizes easy to build, in most cases with a width around 75cm to
minimize the necessity of a top frame border.
Lastly, we can work on a free schedule, between one job and the other.

This are the only reasons our outlet tubs are affordable and the core concept of our double-smile system: you are happy, we are happy too ...!

in you case, 500liters (132 gallons) is the full volume of the tub.
You can subtract 15 gallons for the bather and another 15 if you do not want the water to overflow from top.

You can adjust the amount of water as you like.
Recently, in the land of "up to the shoulder soaking" is becoming popular the half-body bathing (keep the water up to the waist).
In this case you would be able to soak for longer periods and enjoy the minus ion atmosphere originated by the steam rising from the tub.

Thank you for your interest in our japanese soaking tubs.
Please find enclosed some pictures of our standard details. Click on the thumbnails for an enlarged view.

we laminate the wood using wood dowels and epoxy resin (+
curing agent). There are no metal parts.
Adjoining planks are cut together so the cutting angle matches perfectly.

the corner joint is realized with tongue and groove + epoxy resin.
long stainless screws are used to provide extra sturdiness.

Honestly, our tubs do not leak. If you use it regularly (everyday or every other day) your tub will work perfectly without any maintenance.
The only thing you should pay attention to is the fact that wood tubs are vulnerable to dryness. If you leave the tub unused for long periods it may crack. It is difficult to determine exactly at which point critical conditions are reached. It depends on air temperature/humidity, ventilation, heating equipment etc.

In any case, when you leave the tub unused for a week or more (let`s say 4 days or more as a doublesafe), leave 10cm of water inside and you won`t have any problem.

I am sorry you are having some problems with the tub.
About the dust staying afloat, I do not think it is a problem of the wooden tub, although chances are that when you drain the tub, small particles attach to the wood more easily than it would be in the case of an enamel or acrylic tub.

I think you can get rid of these light particles in 2 ways:
1) letting the tub overflow from the top
2) using a thin net to skim the surface of water

About the mold and cracks, please send some pictures, I`d be glad to advice.

I am glad you found a good solution for the tub.
If you apply a coat on the wood note the following:
- The tub will loose its natural "soft" touch
- The tub will loose its aroma and its skin-soothing properties
- You would have to seal it inside and outside (including bottomside) to prevent unbalanced behaviour
- Due to the oils contained in the wood, the coat may not stick uniformly and may detach. Consult also with the maker of the coating product.

Generally we recommend to use it untreated or apply a natural oil to hydratate the surface of the wood.

Additionally there are also some non chemical clear wood treatments which last one year and provide extra protection against mold.

Please let me know if you need some product.
If you have a specific problem, please send pictures of the tub and the installation conditions.

Thank you. If I do not treat it, will it deteriorate more quickly than if I treat it? I like the way it is but am worried about it deteriorating. I am having a cover made for it to keep it out of the weather. However, it got quit a bit of sun last year and cracked in some places. It does not leak, and the cracks are probably natural and not a problem. I like the way it looks now that it has aged for one year. I just wanted to make sure that I'm not supposed to be treating it with something. If there is a natural oil that I should apply, please let me know.

It is not necessary to treat the tub and usually japanese people do not apply anything.
In case you want to restore the original shine you can apply our hiba oil with a cloth, like you would do waxing a pair of leather shoes.

Thanks you for your mail.
Hinoki tubs do not leak unless there is a crack in the wood.
Cracks are caused by dryness. They can be repaired with a sealant:
1) simply clear silicon: it allows movements of wood and it becomes invisible as the crack closes again after normal humidity level has been restored.

2) epoxy putty: it is water resistant and with color similar to wood. But as it is hard, wood balance becomes altered.

Another cause of leaks is poor joint construction. There is not much you can do about it apart for caulking all the inner corners (floor and walls.)Use mildew-proof clear silicon.

It is very difficult to disassemble the tub and most surely you will have to replace some parts. It might be worth the work if you create double tongue/groove rims at every joint but again, the main problem is whether it can be taken apart without damage or not.

(here below we are reporting extracts of the full correspondence for your reference)

About the the horizontal crack: please send me a detailed picture.
Is it in the joint between planks or in the middle of a plank?
How long/wide is it?
Do you think it leaks water?
when did it appeared?
Did you leave the tub dry for long periods?
Once we see the picture we will be able to give you better advice.

Concerning the crack, I went back to the site this morning and took some shots I am sending to you herewith.
To answer your questions:
- it seems to me that the crack is between two planks
- it is the total width of the tub's bottom floor
- it is something like 1mm to 1,5mm wide
- yes, it leaks water unfortunately
- it appeared to us two days ago
- yes we left the tub dry sometimes, and moreover, a week ago we put in service a floor heating that is underneath the tub but also around it. It might have dried the air in the room. Added to a very warm summer here.

Timing of that problem is quite bad since we were ready for handing over the project to the owner client the 1st of september.
Thank you for your advice.

I see: the problem is definately the floor heating.
In general every heating system in the bathroom is bad for the bathtub. It dries up the wood especially if it runs for many hours a day (like central heating systems).
Of course it depends also on the width of the bathroom and height of the ceiling, in any case, we recommend to keep an hygrometer in the bathroom and check regularly.
Floor heating is even worse for the wood tub because the heat tends to concentrate towards the floor and the humidity is washed away systematically as hot air moves upwards.

I recommend to use an underwater epoxy sealant. It should be pushed into the crack with a spackle, to fill it up completely. You may finish the last 1mm with underwater epoxy putty which has a color similar to wood. I could sent you this material by EMS mail but it takes over a week (now customs are full because of holiday period tail).
If you need to repair before sept.1 , try to look for this material locally and let me know if you have problems.

Also, remember not to use the heating when the tub is empty. If you need to, fill the tub with 10cm of water and use the heating without fear.

Thanks for your detailed answer.

I think it would be wiser if you send me the underwater epoxy sealant, and the underwater epoxy putty, that you have already used, and that has already given good results.
If you can do it as soon as possible, and send me the invoice for immediate payment, I would appreciate it a lot.

I checked with my carpenter and he recommends no putty, just make the epoxy fully penetrate. It has a greish color.
after it is dry, you can sand or plane it.
This morning we sent you an EMS parcel. Please let me know if you could fix the problem.

Thank you very much for your product. We received them last wednesday, and the result seems good for the moment. No more leaks!
From the aesthetic point of view, the repair is ok. Sure the color is grey and you can see it if you know it is there, but it is not shocking at all. I will send you a photo tomorrow.

We have not used the hiba oil on the tub yet, but it smells so great in the water.

Cleaning liquid: I am sorry, we do not have this product. In Japan,
as in other countries, hinoki oil is available for aromatherapy in different formats, including a liquid emulsion to be poured inside the hot water to have a hinoki-tub-like aromatic effect.
This is not used for cleaning. Hinoki wood contains within its fibers the resinous product commonly known as hinokitiol. Usage of cleaning products such as detergents or waxes/oils will clog the natural wood pores thus sealing inside the hinokitiol. If you want to take maternal care of the tub, you may wipe it with a towel after use which will prevent any darkening caused by mold.
Then keep a hygrometer inside the bathroom and avoid the relative humidity to drop below 50%.

UPDATE 2008.08.01
See also our news and products page. We have now a natural oil extract which can be used to clean, protect and regenerate the tub.

The japanese tub is a very simple, low tech, minimalist box made out of wood. For this reason it is also very flexible and can adapt to different uses.

In our experience, most of the private clients drain it after use. Anyway one session can be extended for a whole day with the use of tub covers and by adding hot water at need.

Most of the business users add on site recirculating/filtering systems in line with a heater. We do not supply this systems ourselves for the following reasons:
1) US or european makers of pumps/cartridge filters/ozone systems etc. are more advanced than products available in japan
2) Considerations about maintenance and spare parts
3) It is very easy to open a hole in solid wood with the pitch and diameter matching your equipment.

I hope I answered your question. Our tubs are custom made to fit the particular needs/sizes of each site and most of the solutions are evaluated case by case.
Please do not hesitate to contact us for any question or problem.

I understand what you are saying (a stamp stating that the shipper is VAT exempt is required for exports originating in Italy), anyway the japanese customs do not require it.
The shipping is DDU terms (Delivered Duty Unpaid) which already implies that VAT is payable by the coinsignee. On nearly one hundred of shippings we were never required to provide this declaration so to be honest I am not sure how to make it.
Of course I can add a "VAT unpaid in country of origin for exported products" declaration and send you the amended invoice. Is it enough? Do you have any specific requirement according to the format of this declaration?

UPDATE: 2009.05.02
Needless to say that for business users, VAT is paid at the customs ad then refunded or in some cases it is voided when you provide your company information (eg. Belgium). This makes a huge difference for countries with a high VAT (Scandinavian Counties, Belgium, UK and Italy)

Thank you for your interest in our hinoki products.
Sorry, we do not have an ASME sticker. We had 2 cases in the past of exports to Canada requiring a CSA sticker. I think that the client explained the details and could convince the inspector.
This is the first case I hear of such a requirement for the US.
You should keep the line that a hinoki tub is not a hygenical fixture (bathtub), it is rather a health equipment (soaking tub). We are at your disposability, should you have any problem.

UPDATE 2009/1/1
We had two more cases in the US of the building department requiring ASME approval. (California and NY State). In both cases it was explained that the tub is for soaking (like a hot tub) and not for washing. This solved the problem.

As the tub is a manufactured wood product, you should not be required for a Phyto certificate. Anyway we will be glad to supply a declaration stating the origin, treatments and properties of the lumber we employ. Please see here a sample -> PHYTO CERTIFICATE

ADDED 2009/3/12
In recent years there there has been a strenghtening of the rules concerning packaging (crates, boxes). Shipments to Australia, China should be done in non coniferous wood crates otherwise they will be fumigated.
On the other hand, shipments to California cannot use plywood crates due to a very recent restriction on products containing formaldheide.
In any case, we receive constant updates from our forwarder so you will not have to worry about this matter.

We use both cultivated and natural wood. It depends on the type of project, size, quantity etc.
In any case, all the wood comes from sustainably managed areas, some are FSC certified (FSC tands for Forest Stewardship Council).
Hinoki is a coniferous tree and the growth takes about 20-25 years before being commecially exploitable. Farmed wood has the advantage of having few or no thru knots for an optimized usage of the material.
Japanese farmed coniferous wood is a story with lights and shadows.
Back in the 60`s and 70`s, millions of acres of mixed aboriginal woodland has been destroyed to make space for the more commecially exploitable farmed wood for construction.
To add insult to injury, during the 1990`s a weak dollar promoted imports of cheap 2x4 material from Canada, so that japan forestry entered a deep crysis.
After overproduction caused a drop in price, many forested areas ceased to be maintained or were abandoned all-together.
This created a new problem: man-made monocultured-crop forests are not stable ecosystem and the lack of maintenance causes landslides and other disasters.
The bottomline is that there is no point in crying over the poured milk: now the only thing we can do is to use this overstocked farmed wood to bring some relief to the mountain problems and maybe end up saving also some north american cedar forest (or what is left.)

While hinoki is impermeable when cut parallel to the wood grain, transversal sections are 6~8 times more vulnerable to water infiltration.
The traditional joint allows for full coverage of the plank head. Also, plugs and SUS screws can be inserted deeply in the joining plank, making the tub extremely solid and durable.

No, we will not make 45&deg; mitered cuts. It is a weaker joint and is not a proper detail for a hinoki tub. I wish that tubs with mitered corners were not misleadingly called "Japanese tub"...

Hinoki tubs do not leak but may weep when the water is kept inside for a long time or due to condensation. Waterproofing of the floor is not required, but recommended. Anyway I would suggest to use materials such as stone or tiles under the tub.

1) for the plastic wrap, if it is still usable, wrap again the tub and use generously wide tape to seal the openings
If the wrap is badly damaged, you should get some new one from a home center. Close with tape.

2) For the hammer marks: I will need to see the pictures.
Wood swells when it is wet and there is the possibility that it slightly returns back if you blot it with a wet cloth (not just dump, make it dripping wet) or by pouring water on it for at least 1 hour.
If the wood is not returning, you can apply the dump cloth on the damaged area and press it with an iron (cotton-high temperature, apply intermittently for few seconds).

A third option is to sand it. The wood is not treated (excepted for for the bottom plank head). I think you should be able to sand only the faces which are damaged and not the whole top.
The corner fillet (mentori) should be made with a hand plane but this tool is difficult to use. You may employ a sander but be aware that the corner will become roundish instead.

You should pay attention to the following:
The wood is a natural material and is well preserved in a balanced environment. A moisture percentage of 50% is recommended.

If there is scarce ventilation and the humidity is often over 70% your tub is likely to develop mold stains (which can quite easily be removed)

On the other hand, if the environment is too dry (below 40% relative humidity) the tub may crack and cause leakings.

The dryness effects can be mitigated by using the tub daily or leaving it full of water when you leave home for longer periods. Dryness is harmful for wood. Avoid direct and prolonged sunlight exposure and if you have heating system in the bathroom, keep an eye on the hygrometer.

Yes, you can install the tub outdoors, but please avoid as much as possible direct sunlight exposure, expecially when the tub is empty.

Hinoki wood has a unique natural protection against rot, mold and fungi, but you should use some common sense. If the bathroom is not ventilated or if you leave the bathtub full of cold water on a daily base, some stains may appear overtime. No need to worry. Just pour abundant warm water on the area until well absorbed by the wood. Then wipe gently with a cloth sprayed with alcohol for disinfection. The stain will disappear completely.

ADDED 2009.04.22
For toughter stains you can use -wisely- also some bleach for clothes. Wash abundantly with water after application.

The water should be removed when all the members of your family enjoyed their bath. Of course you can leave the water inside until the next day but unless you live in a very dry area, leaving water all the time of course can facilitate the insurgence of some mold stains.

Anyway, best practice is to empty the tub everiday (or at least twice a week if you have a recirculation system), quickly wipe the bathtub with a towel to remove the excess water. Then ensure there is a good natural ventilation (a bathroom with a vindow is strongly recommended) so the wood can adjust automatically its degree of humidity.

Every tub is made to order. We will require a 50% deposit (made by wire transfer to our bank in Japan) to confirm the order. The 50% is calculated on the price of custom made items. Within 30 days we will build the tub and send you by email the photographs of the complete tub / accessories.
Then we will require the balance 50% payment + packing charge + accessories if any (es. bucket, chair...) + transportation charge, as it was shown on the quote.
If you prefer you can use a forwarder you know and we will omit the shipping expenses.

Yes. Each personalized quote includes pick-up in Japan, freight, terminal charges and delivery up to your door (unless you specify otherwise).
The price may not include sales taxes. In most cases you (the coinsignee) will have to fill in a customs application (it can be done by fax) which costs 200-250 US$ and includes sales tax. You will not have to pay any other charge.

Yes, we do ship to the US and to many other countries worldwide. In most of the cases we use air freight. Once the order is confirmed with a deposit, we start to custom build your bathtub. We guarantee the delivery to your home in 6~8 weeks from confirmed order. Shipping is done in a sturdy wood box and it contains the bathtub unit already in one piece for troublefree installation.

To be honest, building a tub is more similar to naval carpentry than a normal plumber job. We do not supply any machine or pump equipment of any sort.I recommend to find locally a pump and cartridge filter. If you replace the water every 3 days or so, you might skip the filter. About the disinfection: do not use chlorine. Ozone seems to be popular, personally I would recommend a salt chlorinator. Please ask a pool equipment dealer near you. I had a client who used 'Aquapure' in a small pool and was very satisfied. It is a product available in the US. See: http://www.jandy.com/html/products/chlorinegenerators/aquapure_faqs.php

There isn`t any direct problem about using salty water in a hinoki bath as long as:
1) once tub is emptied, it should be generously washed with normal water to avoid oxidation and staining
2) we will use stainless screws and plates, so no problem.

Anyway we do not have experience of this and do not know what it will happen in the long span. It may be OK, I do not know. You would have to try at your risk. I feel that salty water would at least alter the aroma and therapeutical properties of hinoki, but this might be just our prejudice.

You have to think of the hinoki tub as a large basinet. It is simply set on the floor and not connected with any piping (a part for the case of a pump). The faucet is wall mounted and the water flows into the tub. Often the drain is not even connected with any fitting: the water flows out from the bottom towards a floor-drain.For the pump fittings: you can let us know the exact location of the outlet and inlet so we can prepare the openings.
Actually, opening the drain hole (of the right size, in the right location) on site is the probably best option as the tub is made of solid wood and opening the hole is very easy.
We do not have availability of fittings with diameter/threading matching the connections of your pump. You should request the pump manufacturer fittings at least 3&quot; long. (the tub wall is 42mm thick). In the worst case, you should be able to have fittings custom made in your country.

Sorry, we cannot supply from Japan heating / filtering / circulation pumps or whirpool systems. Maintenance or replacement of parts would be too troublesome and expensive. You should find one locally and send us the pump specs so we can modify the bath-tub as required. Please note anyway that in most cases a pump is uneconomical and unpratical for private use.

The life span depends very much on the site conditions and care in using it.

A wood tub is built to last 30 years and over of daily use: anyway the average life span is about 10-15 years.
The problems are not caused by water pressure, as we dimension carefully the thickness of the planks and the joints are extremely solid.
If the ofuro is wider than 800mm we use a top beam frame construction.
The causes of aging come from humidity level. If it is too high, it can create stains or mold. If the room is to dry, the wood might crack. Of course cracks can be repaired, but the esthetics is compromised and after 10-15 years many decide to replace the tub.
Keep in mind anyway that ofuros in commercial spas or hotels in japan thus are heavily used, have a long life span because are well mantained. If you check periodically an hygrometer and keep the habit of quickly wiping the tub after every use with a towel, your tub will be strong and even more splendid after 30 years.

Here to the right is the side board (against the wall) of a 15 years old tub we just replaced in a hotel. Considering that it could not be accessed for cleaning, it is still in good condition after all this time!

The japanese hinoki is a very tough wood. It is compact, stable, hard, insect and mold resistant. It does not crack in conditions where other woods crack and does not mold when all woods usually rot.
But it is still a natural material and it is always better to avoid extreme conditions. It is ok if you use it at least once a week.
If you leave your house for a long period follow one of these direction:
1) fill your hinoki tub with 5" of water and leave uncovered.

-or-

2) leave a basinet containing water inside and cover the tub with its lid.

-or-

3) Wrap the exposed sides and top of the tub with clear poliethilen film. Close gaps with tape.

Avoid direct permanent sunlight exposure, expecially when not used. If you keep it always full, you might want to empty it once or twice a week and let it dry for 12 hours.

The knotty and smooth wood have almost the same performance. Should they were to be tested in a laboratory, you will find out that the straight cut hinoki is maybe 10% more resistant than the knotty one. But this is rather an academic problem. You will avoid anyway putting the hinoki in extreme conditions and will enjoy it for 20 or 30 years.

It should add that the knotty hinoki is slightly (again, about 10%) more aromatic than the straight one as knots tend to be rich in resin.

Yes. All our Hinoki comes from the Kiso Valley (Nagano prefecture, Japan): the most precious hinoki production area. Since the 1950`s all tree cutting is done in respect to the environmental sustainability and is subject to strict rules.
Yes. all our bath tubs are handmade in Japan by our skilled &quot;toyo&quot; (master carpenter) using traditional techniques.

No. Can you say that a filet mignon is the same of T-bone steak? Port Orford Cedar, also known as Yellow Cedar, is an appreciated North american wood used for construction and sidings. Anyway, Hinoki (or cypress hinoki) has higher rot resistance and more pleasant grain and color. Moreover, the soft aroma of the Hinoki wood is much more pleasant than the strong smell of the Port Orford Cedar, expecially when warm water is poured on it. For this reason, we may suggest the use of Orford Port Cedar for the wall paneling of the bathroom, but we do not recommend to have a bath tub or the floor duck boards built with this wood.